Halogenated olefin polymers plasticized with a telomer containing perfluorochloroolefin monomer units and method of preparing same



United States Patent-= HALOGENATED OLEFIN POLYMERS PLASTI- CIZED WITH A TELOMER CONTAINING PER- FLUOROCHLOROOLEFIN MONOMER UNITS AND METHOD OF PREPARING SAME William S. Barnhart, Cranforrl, N. J., assignor, by mesne assignments, to Minnesota Mining and Manufacturing Company, St. Paul, Minn., a corporation of Delaware No Drawing. Application December 30, 1953 Serial No. 401,380

24 Claims. (Cl. 260-333) vember 13, 1956, and Serial No. 342,743, filed March 16, 1953, in which detailed description of the methods of producing the plasticizers of this invention may be found.

For the purpose of this invention the term telomer I means both homotelomers and cotelomers. homotelomer refers to those telomeric materials con taining the same monomer units. The term cotelomer refers to those telomeric materials containing monomer units of two or more diiferent monomers. The terms polymerization or telomerization in their broadest sense include both homopolymerization and copolymerization, and homotelomerization and cotelomerization, respectively.

By employing suitable techniques, the various halogenated olefins may be polymerized to produce normally solid thermoplastic compounds. These polymerized halogenated olefins have properties which have lead to their widespread acceptance industrially. The properties of these materials may also be modified, thereby extending the range of their utility, by the addition of compounds which soften or plasticize the thermoplastic material. For

The term example, polymers of trifluorochloroethylene have been plasticized by the addition of a low molecular weight polymer of trifluorochloroethylene in the oil, rease or soft wax range which was prepared by thermally cracking the solid polymer of trifluorochloroethylene. Plasticization of trifiuorochloroethylene using this low molecular weight polymer, was successful but had many serious disadvantages. These prior art plasticizers had limited compatibility with the perfluorochloroolefin polymer which they were to plasticize, produced a hazy or opaque product, were volatile at moderate temperatures and had poor low temperature characteristics. 7

It isan object of this invention to provide a plasticizer for halogenated olefin polymers.

It is another object of this invention to provide a plasticizer for polymers of the perfluorochloroolefins which is more compatible than previously available plasticizers.

It is another object of this invention, to provide a plasticizer which improves the low temperature characteristics of the polymer.

It is another object of this invention, to provide a plasticizer which is not readily volatilized at elevated temperatures.

A still further object of this invention, is to provide a plasticizer which improves the physical characteristics of halogenated olefins.

Various other objects and advantages ofthe present invention will become apparent to those skilled in the art on reading the accompanying description and disclosure.

Generally, the above objects are accomplished by admixing wtih the polymer that is to be plasticized a quantity of a telomer of trifluorochloroethyleue which contains halogen terminal groups. The halogen terminal groups are either chlorine, bromine, or fluorine, preferably chlorine.

The telomeric plasticizers of this invention, are prepared by telomerization in the presence of a sulfuryl halide and have the general formula W--(X),,-W wherein W is a member selected from the group consisting of fluorine, chlorine and bromine, (X) is a haloolefinic, preferably haloethylenic monomer unit and n is an integer greater than one preferably at least 4 and preferably not more than 20.

The reaction occurs essentially as shown below in a typical reaction using chlorotrifluoroethylene and sulfuryl chloride as an example:

As shown, sulfur dioxide gas is formed as well as a clear polymeric mass, usually in gel-like form, which includes various grades of telomeric halocarbons, such as liquids, oils, greases and soft waxes. These telomeric halocarbons may be separated by conventional distillation. The distillable substances obtained by telomerizing chlorotrifluoroethylenic compounds in the presence of sulfuryl chlorides are sufiiciently stable so as not to absorb appreciable amounts'of fluorine even though exposed to the gas for 24 hours at a temperature of 60 C. or to significantly pyrolyticly decompose at temperatures up to 200 C.

This invention also contemplates the use of cotelomers of perfiuorochloroolefins cotelomerized with other halogenated olefins, such as tetrafluoroethylene, trifluoroethylene, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, etc. These cotelomers have the general formula W-(X),,(Y),,,W, wherein W is a member selected from the group consisting of fluorine, chlorine, and bromine, X and Y are different haloolefinic, preferably ethylenic, monomer units and n and m are integers and preferably each is greater than one and each is not greater than 10.

As indicated above, a more detailed description of the process of preparing telomeric compounds may be found in my copending applications. However, a few pertinent examples are presented below:

EXAMPLE l.-TELQMERIZATION OF CHLOROTRIFLUOROETHYLENE subsided. At the end of the telomerization the gases were bled from the system and the liquid product was transferred to a distilling pot. The excess-sulfuryl chloride and carbon tetrachloride (solvent) were-bananas by heating the mixture to 'a pot temperature of C. at atmospheric pressure. The gel-like product was tilled at a vapor temperature up to C. at 35 m mercury to remove very low molecular weight polymers Final distillation was conducted at 0.5 mm. pressure and at a vapor temperature up to about 230 C. The teio;

spe -are merization yield was 78 percent with 93 percent of the product distilled.

EXAMPLE 2.+-PREPARATION OF CHLOROTRI- FLUOROETHYLENE PLASTICIZER This example illustrates the preparation of chlorotri-' fluoroethylene plasticizer. 57 parts of monomer were telomerized with 41.3 parts of sulfuryl chloride and 1.77 parts of benzoyl peroxide. The product .was stripped I of low molecular Weightcomponents by heating the mix- Table I temperature of about 170 C. This temperature is well below the normal molding temperature of this polymer. Since the telomer fraction is volatile at the molding temperature the end product contained only negligible amounts of plasticizer. Again, the high boiling fraction i. e. boiling-above about 250 C. at 0.5 mmJhasRbeeH used as a fusionaid in the preparation of homogeneous films from a dispersion of solid particulate polytrifiuorochloroethylene polymer.

As indicated previously,-the telomerization of 'trifluorochloroethylene with sulfuryl chloride yields-distillable products ranging from volatile =liquids to hard brittle waxes. The molecular weight .of the products varies from about 230 to about 2300 andrep'resents telomers containing from at least 2, and usually about 4, to about 20 monomer units in the chain. All of the telomer chains have chlorine terminal groups. Because the individual fractions .may be of special interest in some instances, the data of Table II are presented below. These data represent the significant physical characteristicsof the specified fractions of telomer product.

PLASTICIZING EFFICIENCY OF CHLOROTRIFLUOROETHYLENE OIL FRA (TIONS 1Com position containing percent plasticircranu 75 percent chiorotrifluoroethylene plastic] shlgre durom eterhardn ess 125, 000. Clear. None. No.

I. These measurements were made upon the original polymeric chlorotrifluoroethylene plastic which contained no plasticizer of any kind ILThese measurements were made upon the polymeric chlorotrifluoroethylenie plastic which contained a plasticizer consisting of low molecular weight chlorotrifluoroethylenic-polymers with extrapolated boiling points of 350 C. to 450 C. at atmospheric pressure (actual measurement 130 C. to 200 0. at 0.5 mm), which were prepared by pyrolyzing higher molecularweight polymers.

H'LThese measurements were made upon the-polymeric ohlorotrifiuoroethylene -plastic which contained a plasticizer consisting of low molecular weight chlorotrifluoroethylene telomers with extrapolated boiling points ot,350 pressure (actual-measurement 130 C. to 200'O.'-at'i).5 mm;),-which telomeriziniz chlorotrifiuoroethylene monomer with suliuryl chloride.

0. to450 C. at atmospheric were prepared by IV. These measurements were made upon the polymeric chlorotrifiuoroethylene plastic which contained a plasticizer consisting of chlorotrifiuoroethylene telomers which extrapolated boiling po1nts300 O. to 550? O. at atmospheric pressure (aetual measurement 95 C. to 270 monomer with sulfuryl chloride.

0. at 0.5 mm.), which were prepared bytelomerizing bhlorotrifluoroethylene V. These measurements were made upon the polymeric chlorotrifluoroethylenc plastic which contained a plasticizer consisting of telomeric chlorotrifluoroethylene from which only the light-polymer ends boiling belowthe extrapolatedboiling point 300 0. at atmospheric pressure (actual measurement 95 C. at 0.5;mm.) were stripped.

VI. T ese measurements were made upon th e polymeric chlorotrifluoroethylene plastic which contained a plasticizer consisting of 'telomeric chlorotrifluoroethylene with extrapolated boiling points above 550 270 C. at 0.5 2pm.). 7

The data of Table 'I compare unpl'asti'c'iaedipolytrifluorochloroethylene and p'olytrifiuoro'chloroe'thylene 'plasticized with a pyrolyticly produced .polytrifiuorochloroethylene oil with the same polymer plasticized with various fractions of the product; ofthe telomerization of trifiuorochloroethylene using ,sulfuryl, chloride as a telomer. The superiority of the telomer plasticized prod- .ucts is quite'apparent. In this connection .it should be noted that the various telomer fractions differ somewhat in the physical properties which they impart to the, solid polymer.

Generally, the telomer fraction used in composition No. 5 is the fraction which will offer a wider range of utilizable properties. However, other fractions of the telomer oil may beused-in (special instances where the properties that they impart ,are desired. :Fcrexample, the fraction boiling below about-95 C. i.ze. ibetween about.-20 C. and about 95C. at 0.5 has been C. at atmospheric pressure (actual measurement Table II PHYSICAL PROPERTIES OF "KEL-F" OILS Telo- Boiling Density Viscosity. cs. Pour mer oil range, Approx. M.P., -pt., trac- 0., at M. W. F. 'F tton 0.5;mm. e F. 210 F. 68 F. F;

1 -20-95 400 1.223 1.720 4.0 2 95-132 570 1.862 1.768 12. 3 3.7 3 132470 can 1.910 1.823 108 14.4 4 -207 800 1.940 1,853 -2.07 was s 207-245 1.1000 1.962 1.873 -157s 27.2 6 245- 1,'600 371.6

= AtTlO" 1 At 210 ,F.

Admixture of the plasticizer withthe polymer thatis For example, the plastici-;

polymerized in the presence of the As indicated previously, the telomeric plasticizers are more compatible than plasticizers prepared by other processes. For example, oily trifluorochloroethylene polymer prepared by cracking solid polytrifluorochlorolll'lll it nal Mlllllllill will tall polymer it ill amount above 35 weight percent. Actually, lower concentrations, that is about 25 weight percent, are employed, since there is a tendency to bleed at the higher concentration. The telomeric plasticizer, however, is compatible in an amount up to about 45 or 50 weight percent with only negligible bleeding and may be used under the most adverse conditions in an amount up to about 35 weight percent with no evidence of bleeding. The amount of telomeric plasticizer that may be used is between about 1 and about 45 weight percent preferably between about and about 35 weight percent depending upon the degree of plasticization desired.

The plasticized polymer powder may be molded using the molding techniques described in U. S. Patents 2,617,149, 2,617,150, 2,617,151, and 2,617,152 issued November 11, 1952, to Louis C. Rubin. In this connection it should be noted that the temperature ranges specitied in the Rubin patent may be appreciably lowered by using the volatile telomer fraction. When molded according to the procedure of the above described patents, or by other suitable molding techniques, the resultant product is a solid polymer of trifluorochloroethylene having the added plasticizer homogeneously dispersed or incorporated therein. The above cited patents also describe the determination and the significance of, the N. S. T. (no strength temperature) values.

While the use of the telomeric plasticizer has been described with particular reference to the plasticization of perfluorochloroolefins, such as trifluorochloroethylene, it should be noted that other halogenated olefinic polymers which contain at least one substituent other than fluorine may be plasticized with equal success. These other substituents may be chlorine, bromine or hydrogen. Thus, polymers of vinyl fluoride, vinylidene fluoride, vinyl chloride, vinylidene chloride, trifluorochloroethylene and copolymers thereof, have been plasticized with up to about 35 percent of the telomeric plasticizer described herein. Previously some of these halogenated olefins, particularly the vinyl compounds, were plasticized with esters of the phosphates and phthalates, such as tricresyl phosphate and di-butyl phthalate. These polymers, plasticized with this type of plasticizer, were highly subject to chemical attack, have very poor electrical properties and thermal stability. When plasticized with the telomeric plasticizer, these halogenated olefins possess excellent physical and chemical properties. Plasticization of these compounds may be effected either by the addition of the telomeric plasticizer alone or, since the telomeric plasticizers are miscible with ester type plasticizers, by blending a mixture of telomeric plasticizer and ester type plasticizers with the polymer to be plasticized.

For example, 75 weight percent of polyvinyl chloride was admixed with weight percent of tricresyl phosphate and 10 weight percent of the telomeric plasticizer used in the formulation of composition 5 of Table I. This plasticized polymer was then molded and found to possess excellent electrical properties, a high degree of resistance to moisture vapor transmission and an unusual degree of resistance to chemical attack.

The unusual properties of the telomeric plasticizers are believed to be due in part to the presence of the terminal groupings. The presence of added chlorine increases the chlorine content of the plasticizer and renders it more compatible with a wider variety of solid polymeric materials. The following analytical data illustrating the difierence between a pyrolyticly produced polymer and telomer is presented below for purposes of information:

ill til Since other theories may be advanced as to the superiority of the telomeric products, it is to be understood that this theory is no to be construed as unnecessarily limiting.

Various alterations and modifications of the invention and its aspects may become apparent to those skilled in the art without departing from the scope of this invention.

Having thus described my invention, I claim:

1. A novel composition which comprises a thermoplastic polymer of a halogenated olefin, said halogenated olefin containing at least one substituent from the group consisting of chlorine, bromine and fluorine, provided that no more than 3 fluorine atoms are present in each halogenated olefin used in forming the polymer and an open chain distillable telomer containing a plurality of perfluorochloroolefin monomer units and halogen terminal groups as a plasticizer.

2. The composition of claim l wherein the thermoplastic polymer is a polymer of vinyl fluoride.

3. The composition of claim 1 wherein the thermoplastic polymer is a copolymer of vinylidene fluoride and another olefin.

4. The composition of claim 1 wherein the thermoplastic polymer is a polymer of vinyl chloride.

5. The composition of claim I wherein the thermoplastic polymer is a polymer of vinylidene chloride.

6. The composition of claim 1 wherein the thermoplastic polymer is a polymer of trifluorochloroethylene.

7. The composition of claim 1 wherein the perfluorochloroolefin is trifluorochloroethylene.

8. A novel composition which comprises a thermoplastic polymer of a halogenated olefin, said halogenated olefin containing at least one substituent from the group consisting of chlorine, bromine and fluorine, provided that no more than 3 fluorine atoms are present in each halogenated olefin used in forming the polymer and as a plasticizer an open chain distillable homo-telomer containing a plurality of perfluorochloroethylene monomer units and halogen terminal groups and having a boiling range between about 20 C. and about 270 C. at 0.5

9. A novel composition which comprises a thermoplastic polymer of a halogenated olefin, said halogenated olefin containing at least one substituent from the group consisting of chlorine, bromine and fluorine, provided that no more than 3 fluorine atoms are present in each halogenated olefin used in forming the polymer and as a plasticizer an open chain distillable co-telomer containing alternating monomer units of a perfluorochloroethylene and another halogenated olefin and halogen terminal groups and having a boiling range between about 20 C. and about 270 C. at 0.5 mm.

10. The composition of claim 9 wherein the other halogenated olefin is vinyl fluoride.

11. The composition of claim 9 wherein the other halogenated olefin is vinylidene fluoride.

12. The composition of claim 9 wherein the other halogenated olefin is tetrafluoroethylene.

13. The composition of claim 9 wherein the other halogenated olefin is vinylidene chloride.

14. The composition of claim 9 wherein the other halogenated olefin is difluorodichloroethylene.

15. A novel composition which comprises a thermoplastic homopolymer of trifluorochloroethylene having an N. S. T. above about 220 C. and an open chain distillable telomer containing a plurality of trifluorochloroethylene monomer units and chlorine terminal groups and 'l elomer 520 C. andabout tillable telomer" containing a .pluralitynof mtri fluoroch1oroethylene monomer units and chlorine terminal groups having a boiling range between about- 20 C. and-about '95 C.'at'0.5mm. I -17.-A-novel composition which comprises athermoplastic homopolymer of trifiuorochloroethylenehaving =ar1 -N.-S."T. above about300C. and-anopen chain distillable *telomer containing a plurality of trifluorochloroethylene monomer units and: chlorine terminal *groups having a boiling range between about 95 C. and about 270 CL-at'0.5 mm. 7 i 18. A novel=composition which comprises 1a thermoplastic 1 polymer *of 'trifiuoroch-loroethylene having "an Ni-S. T: above about'GOOiC; and an open chain distillable telomer containing a plurality of trifluorochloroethylene "monomer units and 'chlorine"terminal groups having a boiling'range'between about 95 C. andtabout 200 C.

.at 0.5mm.

19. A novel 'compositiomwhich: comprises a thermo- "N. S. 'T. aboves'about 300 C.' and an'open chain distillable telomer containing 'a"pluralityof"trifluorochl'oro- .e'thyle'ne monomergunits andichlorine terminal groups boiling above 250 C.at :5 "mm.

20. A novel composition which comprises athermO- 45 weight percent a -dis'tillable open chain -telomer conl ing an N. SKT. aboveabout300 JC. and dispersed therein plastic polymer .of trifiuorochloroethylene having 'an tainin'g" a if plurality? of trifiuoroehioroethylene ""monomer units' and chlorine terminal groups having a boiling range {between about -20' C-."'and '-about 270 C5 atfOfSmm.

zzwnmemageneo s poiyineema s whichfcornprises a thermoplastic ti'ifluerochloroet-hylene polymerhaving an 'NL JS. IE-above about 220 Can'ddispersed-therein in an amount"between-about l'and'about'45 weight-percent a distillable= open chain telomer containingafplurality'of trifiuoroehloroe-thylene -n'ionomer units and chlorine ter- :minalgroups having a boiling-range between about -20 C.:;and about) :270 C."iati 0:5 mm.

,23; A homogeneous.:upolymeramass which comprises a thermoplastic vtrifiuorochloroethylenet.hbmopolymer havin an amount between about 10 andtabout :35 weight tpercent a distillable openchainthomotelomer containing a plurality of trifluorochloroethylene monomer :units and chlorine. terminal groups having a boiling rangetbetween about ,20 C. and.about;270. C. at 0.5 mm. 7

24. A' process for plasti'cizing a thermoplastic polymer of a halogenated olefin,.said halogenated olefin containingat leastone substituent from the groupv consistingpf chlorinepbromine and fluorine, provided that no more than 3 fiuorine atoms are present; in each halogenated olefin usedin forming the polymer which comprises admixing' with-"said thermoplastiqpolymer between about a l anda aboutl' Weight percent ofa-telomer containing a :plurality of trifiuorochloroethylene monomer unitsand halogen" terminal groupings' having a" boiling range between about--20 C. and'about 270C. at 0.5 mm.and

"molding said admixture-under conditionsof temperature and pressure such that a homogeneous polymer-mass is produ'ced.

7 References Cited. inithe file of this patent UNITED STATES'PATENTS 2,440,800 Hanford etal. May 4, 1948 2,543,530 :Kropa, Feb. 27, ,1951 

1. A NOVEL COMPOSITION WHICH COMPRISES A THEREMOPLASTIC POLYMER OD A HALOGENATED OLEFIN, SAID HOLAGENATED OLEFIN CONTAINING AT LEAST ONE SUBSTITUTENT FROM THE GROUP CONSISTING OF CHLORINE, BROMINE AND FLUORINE, PROVIDED THAT NO MORE THAN 3 FLUORINE ATOMS ARE PRESENT IN EACH HALOGENATED OLEFIN USED IN FORMING THE POLYMER AND A OPEN CHAIN DISTILLABLE TELOMER CONTAIONING A PLURALITY OF PERFLUOROCHLOROOLEFIN MONOMER UNIT S AND HALOGEN TERMINAL GROUPS AS A PLASTICIZER. 